The present invention relates generally to the field of faucets. More particularly the present invention relates to the field of automatic on-demand electronic faucets.
Recent trends in bathroom design have begun to stress the importance of using “hands-free” electronic faucets. Hands-free electronic faucets are faucets that do not require the typical physical manipulation of a lever or handle to activate the flow of water. Numerous electronic faucet systems have been developed to accomplish this using various detection systems such as infrared, RF (radio frequency), capacitance, optical, and audio. Hands-free systems thus allow users to operate the faucet without the need to touch the hot/cold on/off knobs.
This hands-free feature for water control provides several desirable features. First, a hands-free system provides improved hygienic properties as a user is not required to physically touch any part of the faucet or basin. This is particularly important in high-traffic locations, such as in the commercial setting. This advantage is also desirable in the residential setting in reducing clean-up and preventing the spread of bacteria.
A second feature of hands-free systems is their ease of use. Often a user would find activation of a traditional faucet knob difficult, i.e. when their hands are slick due to soap or the hands are heavily soiled. Hands-free systems allow a user to simply trigger the sensor to start the flow of water. However, many conventional on-demand systems require a user to place their hands under the faucet to trigger water flow. This arrangement can limit how a user is able to use the device.
A third benefit of on-demand systems is water conservation. All hands-free faucets include an automatic shut-off feature, which may be based on a timer mechanism. Such a feature conserves water and a user also does not need to worry about turning the faucet off. Typically on-demand systems use less water than traditional manual systems, in large part because of user's failure to turn the manual systems off. In some automatic systems, the water only comes on when the user's hands are directly below the water exit point. Thus, the ability to incorporate an automatic off-feature allows for more efficient use of water than is typically experienced with traditional faucets.
Although hands-free systems provide numerous benefits, current systems also fail to provide a user with several desired types of functionality. First, with few exceptions, current electronic systems do not allow a user to control, without manual adjustments, the flow of hot and cold water separately or the temperature of the blended stream which exits the faucet. This can be a particular concern for faucets where cold water for drinking, mild water for hand-washing, and hot water for room cleaning may all be required from the same faucet.
Second, an additional constraint that current systems have is their need for a specific fixed activation zone. Regardless of the type of sensor system used, i.e. infrared, RF, capacitance, RF, etc, the hands-free system will have a certain zone of detection where a “target” needs to enter in order to activate the faucet. Current systems typically include a sensor in a fixed position in the faucet or basin, requiring a user's hands to be placed into the basin detection zone to activate the flow of water. While this may be acceptable for simple hand washing, such a design is ineffective for other applications proximate the sink.
Third, current hands-free systems restrict the aesthetic design of the faucet due to the requirement of a sensor in the faucet as previously discussed. This results in users having less variety of faucets to choose from, which may be of particular concern in residential applications.
Fourth, current systems do not provide for retro-fitting of traditional faucets. Typically, users must undertake the expense of an entire new faucet to enjoy the benefits of hands-free functionality, since the sensor is fixed in the basin of the faucet.